高海拔季节冻土区完全融化期土壤水分特征曲线适用性  

Applicability of soil water characteristic curves during complete melt period in high altitude seasonal frozen soil area

作　　者：张海生 翁白莎[2,3] 严登华[2,3] 栾清华[1] 李文文 邓彬 ZHANG Haisheng;WENG Baisha;YAN Denghua;LUAN Qinghua;LI Wenwen;DENG Bin(Hebei Key Laboratory of Intlligent Water Conservancy,Hebei University of Engineering,Handan 056038,China;State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,China Institute of Water Resources and Hydropower Research,Beijing 100038,China;Yinshanbeilu National Field Research Station of Steppe Eco-hydrological System,China Institute of Water Resources and Hydropower Research,Hohhot 010020,China)

机构地区：[1]河北工程大学河北省智慧水利重点实验室,河北邯郸056038 [2]中国水利水电科学研究院流域水循环模拟与调控国家重点实验室,北京100038 [3]中国水利水电科学研究院内蒙古阴山北麓草原生态水文国家野外科学观测研究站,呼和浩特010020

出　　处：《南水北调与水利科技（中英文）》2024年第2期247-257,358,共12页South-to-North Water Transfers and Water Science & Technology

基　　金：国家自然科学基金优秀青年科学基金项目(52022110;52209049);第二次青藏高原综合科学考察研究项目(2019QZKK0207-02)。

摘　　要：以怒江源区那曲流域为例,基于4个试验场完全融化期(6—9月)的土壤体积含水量(0.15~0.51 cm^(3)/cm^(3))和土壤基质势数据(0~200 kPa)实测数据,选择Van Genuchten(VG)、Brooks-Corey(BC)和Campbell 3个模型进行拟合,以均方根误差ERMS和决定系数R2为评价指标,分析3个模型对高海拔季节冻土区不同土层和不同土壤质地的适用性。结果表明:从整体上看,VG模型(平均R2为0.992,平均ERMS为0.006 cm^(3)/cm^(3))的拟合效果优于BC模型(平均R2为0.972,平均ERMS为0.019 cm^(3)/cm/3)和Campbell模型(平均R2为0.984,平均ERMS为0.014 cm^(3)/cm^(3));但是在不同土层和不同土壤质地情况下模型的适用性有所区别,VG模型更适用于壤土和壤质砂土(平均R2为0.987,平均ERMS为0.008 cm^(3)/cm^(3))以及土壤深层(10~35 cm土层,平均R2为0.990,平均ERMS为0.007 cm^(3)/cm^(3)),Campbell模型更适用于砂质壤土(平均R2为0.985,平均ERMS为0.009 cm^(3)/cm^(3))以及土壤表层(5 cm土层,平均R2为0.993,平均ERMS为0.006 cm^(3)/cm^(3)),BC模型在不同条件下都不是最优模型;参数θr取值大小会显著影响土壤水分特征曲线的形状。本研究可为深入研究高海拔季节冻土区的土壤水分运动特性以及中华水塔区的水源涵养作用提供支持。Determining the soil water characteristic curve in the high altitude seasonal frozen zone is crucial to understand its soil water movement characteristics.However,today's research on modeling soil water characteristic curves in the high altitude seasonal frozen zones focuses more on the effects of permafrost,vegetation degradation and other factors on the change of soil moisture content,and lacks the analysis of the applicability of soil water characteristic curves.The volumetric soil water content and soil matrix potential were measured by in-situ observation experiment selected three models,Van Genuchten(VG),Brooks-Corey(BC),and Campbell for fitting,and analyzed the applicability of the soil water characteristic curve model in the Naqu watershed of the Nujiang River source area using the root-mean-square error and the coefficient of determination as the evaluation indexes.The results showed that:(1)The E_(RMS)of the VG model was 66.6%and 56.9%lower than that of the BC and Campbell models,respectively,and the R^(2)of the VG model was higher than that of the BC and Campbell models(on average,2.0%and 0.9%higher,respectively),and the VG model was considered sufficiently accurate as far as the R^(2)and the E_(RMS)were concerned(R^(2)>0.97,E_(RMS)≤0.011cm^(3)/cm^(3)).While the BC model had an overall poor fitting effect,with an average R^(2)of 0.97 and an ERMS of 0.018cm^(3)/cm^(3),the Campbell model had strong applicability in the soil surface layer,with an average R^(2)of 0.99 and an E_(RMS)of 0.006cm^(3)/cm^(3);(2)The parameterθ_(r)of the VG model plays a key role in the simulation performance of the VG model and its value.The parameterαand the parameter n of the VG model are stable parameters,which have less influence on the shape of the soil water characteristic curve.The parameterθ_(r)of the BC model is also a sensitive parameter,which has a significan influence on the shape of the soil water characteristic curve,while the parameterΦ_(e)of the BC model controls where the segmentation point of the BC model

关 键 词：土壤水分特征曲线 模型优选 土壤质地 Van Genuchten模型 那曲流域 

分 类 号：S152.7[农业科学—土壤学] P642.14[农业科学—农业基础科学]